This plugin provides an implementation of an old version of the Network Information API. It provides information about the device's cellular and wifi connection, and whether the device has an internet connection.
To get a few ideas how to use the plugin, check out the sample at the bottom of this page or go straight to the reference content.
cordova plugin add cordova-plugin-network-information
The
connection
object, exposed vianavigator.connection
, provides information about the device's cellular and wifi connection.
This property offers a fast way to determine the device's network connection state, and type of connection.
function checkConnection() { var networkState = navigator.connection.type; var states = {}; states[Connection.UNKNOWN] = 'Unknown connection'; states[Connection.ETHERNET] = 'Ethernet connection'; states[Connection.WIFI] = 'WiFi connection'; states[Connection.CELL_2G] = 'Cell 2G connection'; states[Connection.CELL_3G] = 'Cell 3G connection'; states[Connection.CELL_4G] = 'Cell 4G connection'; states[Connection.CELL] = 'Cell generic connection'; states[Connection.NONE] = 'No network connection'; alert('Connection type: ' + states[networkState]); } checkConnection();
navigator.connection.type
is set to Connection.CELL
for all cellular data.navigator.connection.type
as Connection.ETHERNET
.navigator.connection.type
is always set to Connection.UNKNOWN
when online.The event fires when an application goes offline, and the device is not connected to the Internet.
document.addEventListener("offline", yourCallbackFunction, false);
The offline
event fires when a previously connected device loses a network connection so that an application can no longer access the Internet. It relies on the same information as the Connection API, and fires when the value of connection.type
becomes NONE
.
Applications typically should use document.addEventListener
to attach an event listener once the deviceready
event fires.
document.addEventListener("offline", onOffline, false); function onOffline() { // Handle the offline event }
This plugin is unable to broadcast events while in the background. Use navigator.connection.type
to check connection status on the resume event instead.
During initial startup, the first offline event (if applicable) takes at least a second to fire.
This event fires when an application goes online, and the device becomes connected to the Internet.
document.addEventListener("online", yourCallbackFunction, false);
The online
event fires when a previously unconnected device receives a network connection to allow an application access to the Internet. It relies on the same information as the Connection API, and fires when the connection.type
changes from NONE
to any other value.
Applications typically should use document.addEventListener
to attach an event listener once the deviceready
event fires.
document.addEventListener("online", onOnline, false); function onOnline() { // Handle the online event }
This plugin is unable to broadcast events while in the background. Use navigator.connection.type
to check connection status on the resume event instead.
During initial startup, the first online
event (if applicable) takes at least a second to fire, prior to which connection.type
is UNKNOWN
.
The code examples in this section show examples of changing app behavior using the online and offline events and your network connection status.
To start with, create a new FileEntry object (data.txt) to use for sample data. Call this function from the deviceready
handler.
Note This code example requires the File plugin.
var dataFileEntry; function createSomeData() { window.requestFileSystem(window.TEMPORARY, 5 * 1024 * 1024, function (fs) { console.log('file system open: ' + fs.name); // Creates a new file or returns an existing file. fs.root.getFile("data.txt", { create: true, exclusive: false }, function (fileEntry) { dataFileEntry = fileEntry; }, onErrorCreateFile); }, onErrorLoadFs); }
Next, add listeners for the online and offline events in the deviceready
handler.
document.addEventListener("offline", onOffline, false); document.addEventListener("online", onOnline, false);
The app's onOnline
function handles the online event. In the event handler, check the current network state. In this app, treat any connection type as good except Connection.NONE. If you have a connection, you try to upload a file.
function onOnline() { // Handle the online event var networkState = navigator.connection.type; if (networkState !== Connection.NONE) { if (dataFileEntry) { tryToUploadFile(); } } display('Connection type: ' + networkState); }
When the online event fires in the preceding code, call the app's tryToUploadFile
function.
If the upload fails, then call the app's offlineWrite
function to save the current data somewhere.
Note For simplicity, file reading & writing was omitted. Refer to the cordova-plugin-file documentation for more information on file handling.
function tryToUploadFile() { // !! Assumes variable fileURL contains a valid URL to a text file on the device, var fileURL = getDataFileEntry().toURL(); getFileBlobSomehow(fileURL, function(fileBlob) { var success = function (r) { console.log("Response = " + r.response); display("Uploaded. Response: " + r.response); }; var fail = function (error) { console.log("An error has occurred: Code = " + error.code || error.status); offlineWrite("Failed to upload: some offline data"); } var xhr = new XMLHttpRequest(); xhr.onerror = fail; xhr.ontimeout = fail; xhr.onload = function() { // If the response code was successful... if (xhr.status >= 200 && xhr.status < 400) { success(xhr); } else { fail(xhr) } } // Make sure you add the domain of your server URL to the // Content-Security-Policy <meta> element in index.html. xhr.open("POST", encodeURI(SERVER)); xhr.setRequestHeader("Content-Type", "text/plain"); // The server request handler could read this header to // set the filename. xhr.setRequestHeader("X-Filename", fileURL.substr(fileURL.lastIndexOf("/") + 1)); xhr.send(fileBlob); }); };
Here is the code for the offlineWrite
function.
Note This code examples requires the File plugin.
function offlineWrite(offlineData) { // Create a FileWriter object for our FileEntry. dataFileEntry.createWriter(function (fileWriter) { fileWriter.onwriteend = function () { console.log("Successful file write..."); display(offlineData); }; fileWriter.onerror = function (e) { console.log("Failed file write: " + e.toString()); }; fileWriter.write(offlineData); }); }
If the offline event occurs, just do something like notify the user (for this example, just log it).
function onOffline() { // Handle the offline event console.log("lost connection"); }